Integrity and function of tissue depend on correct structure of extracellular and cellular components. Mutations in the genes coding for proteins critical for the structure and function of skin result in variety of pathological consequences. In order to understand the mechanisms that lead to loss of function of the dermal-epidermal junction in dystrophic epidermolysis bullosa we have undertaken the approach of analyzing the role of discrete procollagen VII domains in assembly of anchoring fibrils and mechanics of the dermal-epidermal junction. To achieve this goal we will generate a series of procollagen VII variants lacking specific domains. These variants will be then use to map sites critical for adhesion to other macromolecules and for collagen VII self-assembly. Second, we will characterize mechanical parameters of collagen VII monomer. Third, we will create a number of collagen VII mutants that will be used to determine how the single amino acid substitutions alter fibril assembly and change mechanical characteristics of collagen VII. We will also study effects of mutations in connexins that lead to erythrokeratodermia variabilis (EKV) and palmoplantar keratoderma (PPK). We will determine if mutations in connexin 26 and 31 change structure of the protein, disrupt formation of a hexamer and alter transmembrane transport of calcium. The goals of this project will be achieved by pursuing the following Specific Aims: (1) To map structural features in the non-collagenous domain 1 (NC1) critical for the function of collagen VII as an adhesive molecule; (2) To elucidate structural and biomechanical requirements for collagen VII assembly into anchoring fibrils; (3) To determine the effects of mutations in COL7A1 gene on assembly and mechanical properties of collagen VII; and (4) To determine the effects of distinct single amino acid substitutions in connexins on structure, assembly and function.